The goal of cortisol is not to keep us alive for the moment, it's to help us stay alive over a 24 or 48 hour period. We live in a society where cortisol can almost be like constantly flowing through our system. It makes it very hard to be happy when we're in a stressful state because I'm sensitive to pain stimuli. The mind of someone who has a bunch of cortisol in their system is also looking into the future so I can't enjoy the present.